A Clustering Visualization Method for Density Partitioning of Trajectory Big Data Based on Multi-Level Time Encoding

• Published in: Applied sciences 2023-10, Vol.13 (19), p.10714
• Main Authors: Wei, Boan, Zhang, Jianqin, Hu, Chaonan, Wen, Zheng
• Format: Article
• Language: English
• Subjects: Algorithms; Analysis; Big Data; Clustering; Data analysis; Data processing; data visualization; density partitioning clustering algorithm; Efficiency; Forecasts and trends; Geospatial data; Information retrieval; Information storage and retrieval; Methods; Mobile devices; multi-level time encoding; Optimization; Spatial data; trajectory big data; Visualization; Visualization (Computers)
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app131910714

The proliferation of the Internet and the widespread adoption of mobile devices have given rise to an immense volume of real-time trajectory big data. However, a single computer and conventional databases with limited scalability struggle to manage this data effectively. During the process of visual rendering, issues such as page stuttering and subpar visual outcomes often arise. This paper, founded on a distributed architecture, introduces a multi-level time encoding method using “minutes”, “hours”, and “days” as fundamental units, achieving a storage model for trajectory data at multi-scale time. Furthermore, building upon an improved DBSCAN clustering algorithm and integrating it with the K-means clustering algorithm, a novel density-based partitioning clustering algorithm has been introduced, which incorporates road coefficients to circumvent architectural obstacles, successfully resolving page stuttering issues and significantly enhancing the quality of visualization. The results indicate the following: (1) when data is extracted using the units of “minutes”, “hours”, and “days”, the retrieval efficiency of this model is 6.206 times, 12.475 times, and 18.634 times higher, respectively, compared to the retrieval efficiency of the original storage model. As the volume of retrieved data increases, the retrieval efficiency of the proposed storage model becomes increasingly superior to that of the original storage model. Under identical experimental conditions, this model’s retrieval efficiency also outperforms the space–time-coded storage model; (2) Under a consistent rendering level, the clustered trajectory data, when compared to the unclustered raw data, has shown a 40% improvement in the loading speed of generating heat maps. There is an absence of page stuttering. Furthermore, the heat kernel phenomenon in the heat map was also resolved while enhancing the visualization rendering speed.